1. Field of the Invention
The present invention relates to a solar cell roof structure, a construction method thereof, a photovoltaic power generating apparatus, and a building.
2. Related Background Art
In recent years, global warming tendency, exhaustion of a fossil fuel, radioactive pollution by accident of a nuclear power plant and nuclear waste have become problems. Therefore, global environment and energy are rapidly attracting attention. Under such condition, a device, such as a solar cell, for collection of solar energy is expected as an inexhaustible and clean energy source. Particularly, the solar cell capable of installing on a roof of a house had been recently proposed and gradually progressed to spread.
As a form of installing the solar cell on the roof of a building, a method for installing a stand or a fixing member on the roof, which had already been built up, to fix a solar cell panel thereon and a method for installing a photovoltaic device on a sheathing roof board as a roofing material by integration with roof tiles and a metal roof have been proposed.
Among them, the solar cell capable of installing on the roof has a structure by which a power is taken from non-light-receiving surface side as shown in FIG. 12. Respective solar cells become a solar cell module 1 by connecting each other with a wiring member such as a cable. The end of this cable is generally connected to a terminal stand named a junction box 37 for parallel connection.
A direct current output of the solar cell module connected to in parallel in this junction box 37 is converted to an alternating current by a power conversion device 38 named inverter to output to a power line 39 in order to use in a loading device in a power receiving site or to run back to a power company.
However, so far, for performing such wiring, a wire to be extended between the solar cell and a space of the sheathing roof board is provided to an inside of a building, where a junction box and a direct current inverter of the solar cell have been installed. Thus, usually, a through hole in a surface of the sheathing roof board is made to pass the electrical wire through this hole. In addition, it was proposed in Japanese Patent No. 2565611 that an air flowing layer (aeration layer) is formed between the sheathing roof board and the roof panel, an output cable of the solar cell is passed through the space to wire in a ridge of the house.
On the other hand, in a fire resistive structure of a building, a fire preventive construction method of the through portion (penetrating portion) of a fire compartment was, for example, proposed in Japanese Patent Application Laid-Open No. 10-8058 as a method of electric wiring by penetrating through a wall. However, this method has an object of which member around the through hole of the wall has a fire-resistive structure. It is the condition that the wiring member such as the cable is provided vertically against the member comprising the through portion, it is the purpose that flame is shut down by the structure of the wiring member, the wiring member is arranged in a narrow space formed by the solar cell module and a flammable roof base member, and it has not been considered for the case that the electrical wire is drawn into the inside of the building via the through hole from this space.
Generally the following method is applied to the house: on the surface of the roof base member (sheathing roof board), a waterproofing underlaying material such as asphalt roofing is put on to prevent rain water by a double layer structure in combination with a roofing material thereon. The roofing material contributes to prevent water caused by condensation on the roofing material. Therefore, opening the through hole in the sheathing roof board needs a careful construction because the position and size thereof are restricted. On the other hand, when an electric wiring material is penetrated through a space made in the ridge, the wiring length becomes longer to increase an electric resistance causing to problems: an electric loss and an excessive cost for the wiring material.
For the building, a performance to prevent fire spreading is required in consideration of leaping of a fire flame from a neighborhood fire. In the case that the solar cell module is used as a cladding assembly such as the roof or the like of the building, if the structure of the roof and the building does not spread it can be said that the performance to prevent fire spreading is high. However, in case of installing the solar cell module on the roof, the back of the solar cell and the common roofing material, which is roofed with, has such electric wiring as the cable to send the electric output generated thereby. Via the through hole, the wiring material is taken into the space at the back of the sheathing roof board. Normally in this portion, a plurality of cables is contained. In an event of an accident, when leaping of a fire flame from a neighborhood fire causes the solar cell module to be exposed to a high temperature to be deformed, the solar cell module may contact directly a plurality of cables resulting in possible heating by heat conduction. Further, the through hole allowing easy flow of air containing more oxygen, in which many cables center, possibly becomes a weak point for fire prevention particularly when the cables are not of a flame-retardant material. Therefore, a method of attaching a metal plate to the back of the solar cell to limit deformation in the least degree has been applied so far. In order to prevent deformation, the mechanical strength of the metal plate should be increased. Consequently, there is a problem that the degree of designing the solar cell module itself is decreased.
The present inventors have studied on the aforementioned problem to be solved, and as a result, they have found as effective that an origin of fire keeps enough distance from a plurality of cables and a structure thereof capable of preventing flow (aeration) of fresh air from outside as possible, and they have found that the following structure is the best.
According to a first aspect of the present invention, there is provided a solar cell roof structure comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, the solar cell roof structure further comprising a base sealing member on the roof base, for covering the through hole, wherein an exit in the base sealing member through which the electrical wire extends into the space between the solar cell module and the roof base is provided at a portion of the base sealing member other than a portion just over the through hole of the base sealing member.
According to a second aspect of the present invention, there is provided a method of constructing a solar cell roof comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire being drawn into a space at the back of the roof base through a through hole provided in the roof base, the method comprising providing a base sealing member on the roof base, for covering the through hole, and providing an exit in the base sealing member through which the electrical wire extends into the space between the solar cell module and the roof base at a portion of the base sealing member other than a portion just over the through hole of the base sealing member.
According to a third aspect of the present invention, there is provided a photovoltaic power generating apparatus comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, the apparatus further comprising a base sealing member on the roof base, for covering the through hole, wherein an exit in the base sealing member through which the electrical wire extends into the space between the solar cell module and the roof base is provided at a portion of the base sealing member other than a portion just over the through hole of the base sealing member.
According to a fourth aspect of the present invention, there is provided a building comprising a solar cell module above a roof base of the building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, the building further comprising a base sealing member on the roof base, for covering the through hole, wherein an exit in the base sealing member through which the electrical wire extends into the space between the solar cell module and the roof base is provided at a portion of the base sealing member other than a portion just over the through hole of the base sealing member.
According to a fifth aspect of the present invention, there is provided a solar cell roof structure comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, wherein a base sealing member comprising a heat-resisting or fire resistive material is provided on the roof base, for covering the through hole.
According to a sixth aspect of the present invention, there is provided a method of constructing a solar cell roof comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire being drawn into a space at the back of the roof base through a through hole provided in the roof base, the method comprising providing a base sealing member comprising a heat-resisting or fire resistive material on the roof base, for covering the through hole.
According to a seventh aspect of the present invention, there is provided a photovoltaic power generating apparatus comprising a solar cell module above a roof base of a building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, wherein a base sealing member comprising a heat-resisting or fire resistive material is provided on the roof base, for covering the through hole.
According to an eighth aspect of the present invention, there is provided a building comprising a solar cell module above a roof base of the building, an electrical wire for the solar cell module provided in a space between the solar cell module and the roof base, the electrical wire extending into a space at the back of the roof base through a through hole provided in the roof base, wherein a base sealing member comprising a heat-resisting or fire resistive material is provided on the roof base, for covering the through hole.